The average price for a gallon of diesel dropped 0.6 cents to $3.027 for the week ending Aug. 27, according to the Energy Information Administration.

The California region saw the sharpest decline, down 2.1 cents to $3.20. The Rocky Mountain region, where farmers ramped up diesel demand to run irrigation equipment and the transition to ULSD has proved challenging, remained the most expensive region in which to fill up at $3.346, after a modest 0.3-cent decline.

Not all regions posted rollbacks, as the Lower Atlantic region prices increased 0.7 cents to $2.897. In spite of this, that region remained the cheapest in which to fill up.